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Part III. — Eighteenth Annual Report 



poda galei. The maxilke (fig. 32) are small, and have the end-joint 

 armed with two moderately elongate and stout terminal spines. The 

 anterior foot-jaws (first maxillipedes, fig. 33) are more slender and rather 

 more elongate than those of Lernceopoda galei (fig. 34). 



The male of Lernceopoda cluthce differs considerably from that of 

 Lernceopoda galei, or Lernceopoda bidiecalis, and especially so in the 

 structure of the abdomen and caudal appendages. In the male of 

 Lernceopoda cluthce the abdomen is distinctly segmented, and the caudal 

 furca consists of two slender processes, while in the two other species 

 named the furca assumes the form of broadly oval, or club-shaped, 

 appendages, divergent and reflexed upon the abdomen (fig. 37). 



The female specimen represented by fig. 28 measures, from the front of 

 the head to the end of the posterior thoracic appendages, 5mm., and from 

 the termination of the same thoracic appendages to the extremity of the 

 elongated second maxillipedes about 8mm. The posterior thoracic 

 appendages are scarcely 1mm. long, and the length of the ovisacs, which 

 varies considerably in different specimens, is scarcely 4mm., in the one 

 represented by the figure. 



Habitat. — Attached to the gill- filaments of the Fuller's Kay, Rata 

 fullonica, captured in the Firth of Clyde in April 1897. 



This Lernceopod is quite distinct from any of the other species recorded 

 here. The form of the female ; the form and armature of its mandibles, 

 maxillse, and first maxillipedes, and the general structure of the male, all 

 differ from any other species of Lerna'opod known to me. 



Besides the species of Lernceopoda recorded in the preceding notes, 

 there are other two forms which for the present will have to stand over, 

 as there has not been time to study their characters sufficiently to allow 

 of their being included in the present paper. One of these forms was 

 obtained on the gill-filaments of the grey slate, Rata batis ; the other 

 was obtained on the gill-filaments of the cuckoo ray, Rata circularis, 

 both from the Firth of Clyde. 



Genus Brachiella, Cuvier. 



This genus differs from Lernceopoda in having the cephalo-thorax more 

 or less elongated and moderately slender. The arms (second maxillipedes), 

 are, as in Lernceopoda, usually separate except at the ends where they are 

 united to a hard horny button, which serves to anchor the parasite to its 

 host. In some of the species at least there are two pairs of caudal 

 appendages. 



The following are the species of Brachiella that have come under my 

 observation : — 



Brachiella rostrata, Kroyer. (PI. VIII., figs. 38-39.) 



1837. Brachiella rostrata, Kr., Naturh. Tidsskr., r. i., vol. i., 



p. 207, PL II., fig. 1. 

 1864. Brachiella rostrata, Kr., op. cit., r. iii., vol. 2, p. 364, PI. 



XVII., fig. 8. 



A number of specimens of this fine species have been obtained on the 

 gills of large halibut, Hippoglossus vulgaris, brought to the Fish Market 

 at Aberdeen. In the female of Brachiella rostrata, the mouth-organs 

 have a close resemblance to those of Lernceopoda. The mandibles and 

 maxillse of this species are somewhat similar to those of Brachiella 

 insidiosa. The antennae, which are moderately stout, do not show much 

 structural development, and the anterior maxillipedes though short have 

 moderately strong terminal claws. 



